I think this is going to be the next big problem - what does "success" look like and when can a country return to normal life? Zero cases for a day or two means nothing. Even if zero cases are sustained for weeks within a single country, once cross-border travel is resumed, new infections are bound to happen. Perhaps isolating the most vulnerable populations and "embracing" the virus for the rest would have been a better / less disruptive approach in the longer term.